Static eliminator



Patented Sept. 1, 1931 l ELMER n. BISHOPYAND FRED c BRooK, 'on ID'IANAPQLIS, NDIANA 'sTA'rIo 4 ELIMNATOR Application led vFebruary3.25,H1929. LSerial No. 342,436.

'' Tv5 especially intended for use ein, connection with radio receiving sets and circuits for eliminating the static interference from the incoming signals.

The static 'eliminator herein disclosed is ic cimiiacia ccfac acct-ccas tc that aiccicaca ic an application of Lulu H, Bishop for Lets ters Patent of the United States" on radio reception, Serial No. 265,591, tiled March 29, i928, admcictfatfix cf thc estate cf J ames;

*i5 A. Bic-iacpf Ia that acciicaticc cacca ic aiaclccca an arraagcmcnt in which thc incoming signals' arc carried throng 1a conductor `cli conductors in proximity to a magneticfleld or fields so that the static interference is 2o drawn away ffcm said vconcluctcrc by a mag:

netic action. The static' interference is thus separated v from the true radio signals, allowing the latter in substantially undiminishe' ild iii- 'giitly' C lfifld 'O'Ini and ti t0 ell- "as ter thcj translating apparatus' of thc SySt-m In the arrangement disclosed in vthat earlier application, thc conductor cr conductors are carriedthrough tubular magnetic shields which afevin turn subject to the control and va inflacncc cfiaagcctc whcrcby they atc maignetizc'd, and in the arrangcmcntof that ap plication these magnets are illustratedl as being of electro-magnetic influence. Furthermore, in the arrangement of that earlier application ofthe magnetic shields and all portions of each shield are subjected to the same magnetic polarity. y f

According' to one' feature of the present improvements we 'have provided an arrange` I'nentin which the tubular magnetic shields are subjected to both positive and negative magnetic influences so that each of said tubular magnetic ieldsicon'stitu'te's aportion of a magnetic circuit through which the niagnetic lines of force flow from one pole of the magnet to the other. That is to say,` each of the magneticshields is simultaneously subjected to thel influences of both positive and negative magnetic polarity, whereas in the aforesaid earlier application each of said shields is subjected at all points to one and the `same 'polarity.` y

Furthermore in the present arrangement We have found it possible to make use of permanent magnets for generatingthe mag 55 rietic fields, and we arecenabled to do this largely because ofthe fact that each of the magnetic' shields is subjected to ,both the positive and negative magnetic iniiuences. if Permanent horseshoe magnets of relatively small size can thus be used with very satisfactory results, and magnets of this kind cao beproduced which -vvill be suliiciently powerful and permanent to give very fine and lasting operation.`

further feature of the invention relates to accomplishing a very@ complete Vand thorough velimination ofthe objectionable staticinfluences.` i Otherr objects and uses l of the invention will appear from the detailed description which consists of the features of construction and combination, of parts hereinafter described in the claims.

the. drawings:

Figure l shows a plan view of a device emodying Vthe features of the present invention; Figure 2 shows a fragmentary side eleva# tion corresponding to Figure 1 but on enlargedscale; And Figure shows a cross section on the line 3-3 of Figure l, looking in the direction of the arrows, but on enlarged scale.

We have shown the `features of our invention as incorporated within astructure including two units, t and 5 mounted upon a common baseboard 6. Said baseboard is preferably madeof wood, liber, composition material, or other suitable material, pref- 90 .erably of `a non-magnetic nature,

Each ofthe units aand 5 includes a horse- Vslice permanent magnet 7 the poles 8 and 9 of which arev brought into parallelism in the usual manner. yAlso said poles are prefera- 9J blyof alternate polarity as indicated by the markings shown' upon them.

[Secured to the top and bottom faces of eachV ofthe magnetic poles there is a plura'lty of relatively thin sheets or laminations L l 10 of magnetic material such as a high grade of soft iron. The number of these laminations in each vgroup will depend upon the number of tubular magnetic shields of such group. The number of laminations on each magnet pole should be equalV to the number on the other end.

`Each of the tubular magnetic shields comprisesV a coil or helix 14 of magnetic wire such as soft iron wire. The same 'is wound into a close coil of proper diameter and of proper length to overlie the laminations reaching out from the North and South poles of the magnet in question. This general arrangement will be well understood from examination of Figure l.

The end portions 15, of the laminations are coiled around the respective tubular magnetic shields so as to accomplish the two purposes of holding said shield securely in place and` at the same time establishing a thorough magnetic contact therewith.

vThe successive laminations of each bunch are of progressively shorter lengths as best shown in Fig. 2 so that the tubular magnetic shields will be located side by side to each other when secured in place. This is well illustrated in Figure 2.

From the foregoing it will be evident that the number of laminations from each pole is equal to the number of tubular magnetic shields of that unit.

It will also be evident that the magnetic flux passes from each North pole to the other corresponding South pole, passingas it does so through all of the tubular magnetic shields of that unit.

An aerial or antenna wire or wires 16 are threaded through the shields in the proper manner to effect the elimination and remove all staticiniiuences. Thel principles of this Aoperation are similar in some respects to those disclosed in the aforesaid earlier application for Letters Patent of the United States. In this connection the aerial conductor is preferably threaded back and forth through the top and bottom tubular shields of'each unit in succession so that when the conductor is completely interwoven wit-h the shield it will present an appearance such as shown in Figure 2 when viewed from one side.

It will'be found that the static interference or influence is drawn into the magnet poles and may be thence discharged into the ground or atmosphere. For this purpose the poles of the two units are shown as being electrically connected together by a conductor l?, and there is also shown anotherconductor 1S which may be grounded. l

We have found by experimentation kthat this type of construction may be made amply strong for all practical requirements as far as the magnetic connections are concerned, and that the construct-ion herein disclosed may be incorporated iinto a very compact and relatively small structure.

While we have herein shown and disclosed only a single embodiment of the features of our invention, still we do not intend to limit ourselves in the same except as we may do so in the claims.

We claim: 1

1. In a device of the class described the combination of a horseshoe shaped permanent magnet, equal numbers of laminations of magnetic material projecting from and .secured to the polar surfaces of said magnet,

tubular shields of magnetic material extending between corresponding laminations projecting from opposite magnetic poles, a con.- ductor for radio frequency currents threaded through the tubular magnetic shields in sequence, and a ground connection tothe magnet, substantially as described. Y.

2. In a device of the class describedthe combination of a horseshoe shaped' permanent magnet, a series of laminations of magnetic material secured to and projecting from each magnetic pole, the number of laminations in one series being the-same as that in the other series, tubular shields of magnetic material extending between corresponding laminations reaching from the two poles of the magnet, Aand a conductor for radio frequency currents threadedthrough said magnetic shields in sequence, substantially as described. Y

3. In a deviceof the class described, vthe combination of a horseshoe shapedmagnet, ay plurality of laminations secured to vand extending outwardly from each pole ofv said magnet, tubular shields of magnetic material extending between the laminations' of the two poles, and a conductor for radio freiquency currents extending through Vsaidl magnetic material extending between laminations of the two poles, and a conductor for radio frequency currents extending through the tubular shields in succession, substantially as described.

5. In a deviceV of thev class describedl the combination of a-pair of magnet poles of opposite polarity, a series of tubular shields of magnetic material having their endrportions magnetically connected to the opposite magnetic poles, and a yconductorl for radio frequency currents threadedV through said tubular shields in succession, substantially as described.

f `6'. In a device of the class'described 'the combination of apair of magnetic poles of opposite polarity, a tubular shield of magnetic material having its opposite ends in magnetic connection'with said opposite magnetic poles, and a conductor for radio frequency currents extending through said shield, substantially as described.

7. In a device of the class described, the combination of a pair of magnetic poles of opposite polarity, a tubular shield of magnetic material joining said poles together and constituting a portion of the magnetic circuit, and a conductor for radio frequency currents extending through said shield, substantially as described.

8. In a device of the class described the combination of a pair of magnetic poles of opposite polarity, tWo groups of tubular shields of magnetic material lying in parallelism and having the end portions of each said shield magnetically connected to the opposite magnetic poles, and a conductor for radio frequency currents extending through said tubular magnetic fields, substantially as ELMER E. BISHOP. FRED J. BROOK.

described. 

